Stuck subframe bolt.

[MarkSims]

One of the 4 bolts connecting the subframe to the frame won't budge. The head takes an allen wrench and it's stripped out now. The bolt goes through a nut that is welded to the frame.

I've drilled a hole through the bolt and tried an extractor bit but my 4 amp, 3/8" drill won't turn once the extractor bites and starts burning up. I tried a 9 amp, 1/2" drill but the chuck slips around the bit once it bites - no matter how tight I try to get the chuck.

I've searched the posts and have a plan - but I'm not optimistic. Let me know if you have any suggestions!

1. The gas tank is removed. Drain the gear oil and lay the bike on its side - with the end of the bolt sticking through the nut pointing up.

2. Apply penetrating oil to the exposed threads of the bolt and to the lip of the nut. Apply heat to the head of the bolt to draw the oil between the nut and bolt. (Does that really work?)

3. Repeat step 2 several times over a couple of days.

4. Try the extractor again.

There was also a lot of talk about using heat - but I wasn't clear on that. Should heat be used on the nut just prior to trying the extractor? Or is the idea to use heat and cooling cycles on the nut and bolt to get them to break their bond?

Thanks! Mark

 

[Moto Squid]

heat up just the nut so it expands and not the bolt...then start wrenching on the bolt and it should break free. You might want to try these nifty little sockets from craftsman. They've got reverse flukes, that when put on a stripped bolt head, turn and dig into. The harder you try to break it free the tighter they'll grab. Or drill the head off of the allen bolt, get the sub out of the way, and monkey around with an easyout.

 

[MarkSims]

The subframe bolt head is tapered so there's not much stickout out of the frame. I'm not sure that the craftsman socket will be able to get a bite on the head - but I'll give it a shot.

 

[Scoob]

One of the 4 bolts connecting the subframe to the frame won't budge. The head takes an allen wrench and it's stripped out now. The bolt goes through a nut that is welded to the frame.

I've drilled a hole through the bolt and tried an extractor bit but my 4 amp, 3/8" drill won't turn once the extractor bites and starts burning up. I tried a 9 amp, 1/2" drill but the chuck slips around the bit once it bites - no matter how tight I try to get the chuck.

dude, extractors arent meant to be used in drills, you should be turning the extractor with a wrench... you'll get more torque with a wrench and wont wreck your drill... whether it's the square type or the left hand screw type, make sure to tap the extractor into the bolt with a hammer so that it doesnt slip when you try to turn it

 

[MarkSims]

Okay, thanks. The end of the extractor is square - about 1/4 inch on each side. I didn't use a wrench because I wouldn't be able to get enough leverage on a short wrench- but I just realized that I should slip a piece of pipe over it for leverage.

Thanks for the tip on the tapping. I had tried to use a larger extractor but it wouldn't bite (just spun) - I suppose it would have if I had tapped it in. I think I'll go back to the larger extractor bit.

Larger is better, right?

 

[Flyboy500]

Look for some stuff called Aero Kroil... Comes in an orange can. Amazing penetrating oil and I have never found anything any better. PB Blaster oil sucks... Good luck... You'll get it. Bigger hammer and some serious heat will do the job.

 

[Patman]

Actually the extractor is designed for a tapping handle. You can really bite down on the square shank and should be able to apply plenty of torque in an even manner instead of from one point like a wrench.

 

[Patman]

What's a tap handle?

http://www.sears.com/sr/javasr/prod...0&vertical=TOOL&pid=00952559000&bidsite=CRAFT

Why an inexpensive tap handle is not included with extractor sets I'll never know. :|

 

[MarkSims]

Before trying the drill, I was using a tap handle on the extractor bit. No matter how much I tightened the handle, it would slip around the bit as I gave a lot of pressure.

A 7mm wrench fits the bit pretty good. I'm going to pick up a pipe and try that tonight.

Thanks for the replies!

 

[mach1]

Flyboy's on the mark with the Aero Kroil. Great stuff. Also, as the penetrating oil is soaking in, periodically tap the nut and whatever is left of the bolt head with a hammer. The vibration helps break the bond between the fasteners and helps the oil penetrate. As far as using heat, I've had alot of luck spraying circuit cooler on the bolt while applying torch heat to the nut. Circuit cooler comes in a spray can and can be found at radio shack etc. It won't carry all the bolt heat away but sometimes will keep the bolt from expanding just enough to make a difference. Good luck.